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United States Patent Application |
20110224792
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Kind Code
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A1
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Groeger; Achim
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September 15, 2011
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ARTIFICIAL MUSCLE
Abstract
The invention relates to an artificial muscle made of aplurality of
nano-motors (referred to hereafter as nano power cells), wherein the
nano-motors are the smallest unit for the production of complex muscular
structures for generating longitudinal motor forces. The artificial
muscle according to the invention is made of nano-motors (nano power
cells), formed of symmetrical individual plates formed as double
triangular segments and arranged radially in a honeycomb pattern, said
plates being displaceable in the center and comprising an expansion unit
in the interior thereof.
Inventors: |
Groeger; Achim; (Orionstr, DE)
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Serial No.:
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062133 |
Series Code:
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13
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Filed:
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April 15, 2009 |
PCT Filed:
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April 15, 2009 |
PCT NO:
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PCT/DE09/00519 |
371 Date:
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May 23, 2011 |
Current U.S. Class: |
623/14.13 |
Class at Publication: |
623/14.13 |
International Class: |
A61F 2/08 20060101 A61F002/08 |
Foreign Application Data
Date | Code | Application Number |
Sep 3, 2008 | DE | 102008045554.7 |
Jan 29, 2009 | DE | 202009001086.4 |
Claims
1. An artificial muscle, comprising: at least one nano-motor being formed
from an expansible outer shell comprising stable longitudinal structure;
and an expansion unit arranged within an interior of the outer shell.
2. An artificial muscle in accordance with claim 1, wherein the outer
shell comprises six rhombic individual plates that are affixed to one
another by flexible connections.
3. An artificial muscle in accordance with claim 1, wherein the expansion
unit comprises a film comprising inlays of liquid crystals of
ferromagnetic elastomers comprising electroactive polymers.
4. An artificial muscle in accordance with claim 3, wherein the film is
coiled radially.
5. An artificial muscle in accordance with claim 4, wherein the film
comprises at least three layers, wherein outer layers comprise a
non-conducting material, the surface of which is coated on both sides
with an electrically conducting material, and an intermediate layer
comprises the liquid crystals of charged ferromagnetic elastomers.
6. An artificial muscle in accordance with claims 1, wherein the
expansion unit comprises a contraction rubber including at least one
nematic elastomer coil comprising inlays of liquid crystals.
7. An artificial muscle in accordance with claim 6, wherein the expansion
unit is configured as a cylindrical hollow body and is provided all the
way around with the at least one nematic elastomer coil being arranged
along the surface of the hollow body.
8. An artificial muscle in accordance with claim 7, wherein arranged
inside the expansion unit that is configured as a cylindrical hollow body
is a heating device or a laser light source, and each of the expansion
unit and heating device or laser light source is connected to mechanical
couplings positioned at ends of the nano-motor outer shell via an
electrical connection.
9. An artificial muscle in accordance with claim 2, wherein integrated on
the end faces of the outer shell are mechanical couplings comprising
electrical plug-in connectors serving to hold end area portions of the
rhombic individual plates.
10. An artificial muscle in accordance with at least one of the foregoing
claims, wherein the outer shell is provided with a spring-loaded
covering.
11. Artificial muscle in accordance with claim 10, wherein the
spring-loaded covering comprises a non-conducting plastic functioning as
an insulator for the nano-motor and promotes mechanical compression.
12. An artificial muscle in accordance with claim 1, wherein a space
between the expansion unit and the inside of the outer shell is filled
with a flexible plastic.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to an artificial muscle that comprises a
plurality of nano-motors (referred to hereinafter as nano-power cells),
wherein the nano-motors are the smallest unit for producing complex
muscular structures for generating longitudinal motor forces.
[0002] Complex structures such as for instance a muscle, the action of
which is created from a plurality of serial and parallel nano-power
cells, may be used for many different purposes such as for instance in
prosthetics. Muscular structures whose properties are consistent with
human and animal muscles can be produced based on the small nano-power
cell. Lift and rotational movements are produced by the progress of the
muscle structures.
[0003] In addition to employment in the field of prosthetics, the
nano-power cell may be employed in all fields in which a longitudinal
pulling force development can be used. This also applies to rotational
movement sequences, the movement of which is produced from a plurality of
longitudinal force machines.
[0004] Known from DE 36 44 481 A1 is a drive unit for movement mechanisms
that may be employed with nothing further than as an implant in the field
of biomedical engineering.
[0005] In this case the force generation element may be used as a muscle
prosthesis. In the drive unit described, there is at least one force
generation element that has an interior cavity closed by stiff end parts
for limiting its working volume and of which one section can be securely
connected to a first part of the mechanism and another section can be
connected, in a tension-proof manner, to another part of the mechanism in
order to effect a change in the relative position of the parts, and with
a control unit for changing the working volume of the force generation
element, wherein the force generation element has a radially elastic
hose-like jacket, the longitudinal extension of which is limited by a
support structure so that using the control device the inner
surface-to-volume ratio may be changed with longitudinal change
(.DELTA.L) of the force generation element.
[0006] The longitudinal jacket is connected at its end to rigid plates,
whose interval may be changed by raising or lowering the internal
pressure so that either a shortening movement or a movement returning to
the original length of the force generation element results. The
individual elements are connected by a fluid connector to one end of the
force generation element. Due to the smaller dimensions of the force
generation elements, the fluid connectors must be embodied relatively
thin, that is, like capillaries, so that a pressure can change only
slowly, which, using the example of a muscle, leads to chameleon-like
movement speeds.
[0007] Although muscle groups may be formed with round structures, they
have disadvantages when performing rotational movements. Round structures
for expanding bodies are not suited for rotational movements, for
instance arm or foot rotation, because in the case of transversely
arranged muscles, at the moment of force generation these structures pull
into one another and thus the force required is consumed inside the
muscle.
[0008] Generating the pressure represents another disadvantage. The units
for generating the required pressures (pneumatic, hydraulic, etc.) must
be embodied relatively large so that including these on a moving body is
problematic.
[0009] Movement sequences, like for instance of the human skeleton, are
fundamentally based on pulling movements. For using high-performance
active elements (electroactive polymer (EAP) actuators, with varying
characteristics or the nano-technology of the natural muscle), like of
liquid crystals made of ferroelectric elastomers that permit rapid
movement and are not sensitive to the environment, a design is necessary
that converts a pressure action to a pulling action. For using
high-performance nematic elastomers, with varying characteristics or the
nano-technology of the natural muscle, like the nanotechnology of liquid
crystals made of nematic elastomers, which permit rapid movements and are
not sensitive to the environment, a design is necessary that produces a
direct pulling action and that makes it possible to perform this action
micromechanically in a non-positive fit.
SUMMARY OF THE INVENTION
[0010] The technical problem addressed by the present invention is based
on an extremely low-power drive with simultaneously high output power.
The design of the nano-power cell drive is such that the latter is
externally constructed such that the drive is tactilely very soft and
visually is very similar to human and animal muscles.
[0011] The object and goal is a drive that is biologically similar to
muscular structures and that has low power consumption for employment in
a wide variety of technical and bionic fields.
[0012] The drive is formed from a plurality of nano-motors (nano-power
cells).
[0013] The nano-power cell forms the smallest unit for producing complex
muscular structures for generating longitudinal motor forces that convert
a pressure action (polymers) into a pulling action or stabilize a
contraction rubber (elastomers) such that the nano-power cell is
stabilized in a non-positive fit as for the polymers.
[0014] Complex structures, such as for instance a muscle, the action of
which is formed from serial and parallel nano-power cells, may be
employed in diverse uses, such as for instance in prosthetics, internal
medicine, robotics, engineering, etc. Muscular structures whose
properties are consistent with human and animal muscles can be produced
based on small nano-power cells. Lift and rotational movements are
produced by the progress of the muscle structures.
[0015] The nano-power cell comprises a honeycomb-like jacketing in which
is embedded the expansion unit that has been coiled in a spiral. The
liquid crystal molecules are bound into polymer networks such that the
latter exert a lifting action when an electrical field is applied. The
expansion unit comprises a coil in which liquid crystals of ferroelectric
elastomers are bound.
[0016] By applying an electrical field of 1.5 kV/mm to the liquid
crystals, a volume expansion, currently approximately 4%, occurs in the
nano-power cell. In practice the working voltage is in a range that is
not harmful to humans or animals, that is, less than 25 volts.
[0017] By reducing the electrical field, the volume expansion returns to
its original condition. The radial expansion that occurs in the center of
the cell leads to the shortening of the nano-power cell, which is used as
force for the movement sequences. Other variants from the EAP family may
be used for the expansion unit, as well.
[0018] Another option for embodying the expansion unit is to design it as
a contraction rubber comprising at least one nematic elastomer coil that
is embodied with inlaid liquid crystals. The expansion unit embodied as a
contraction rubber is embodied as a cylindrical hollow body that is
provided all the way around with at least one nematic elastomer coil
arranged along the surface of the hollow body.
[0019] Arranged inside the cylindrical hollow body is a heating device or
a laser light source. It is connected to the mechanical couplings via an
electrical connection.
[0020] The expansion unit comprises at least one nematic elastomer coil in
which liquid crystals are bound and a heating device or laser light
source is arranged in the interior of the elastomer coil. The nematic
elastomer coils are heated or activated with the laser by applying a
working voltage to the heating device or laser light source, which leads
to a shortening of the nano-power cell and thus to a radial
circumferential expansion in the center area.
[0021] In practice, the working voltage is in a range that is not harmful
to humans or animals, that is, less than 25 volts. By decreasing the
working voltage, the longitudinal change returns to its original status.
The shortening of the nano-power cell leads to radial expansions that
occur in the center of the nano-power cell and leads to the natural
expansion of the muscle and at the same time to stabilization of rotating
forces for the movement sequences.
[0022] The goal of the expansion unit is to reproduce the nano-motor
muscles of living organisms like humans.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1: is an exterior view of the nano-motor (nano-power cell);
[0024] FIG. 2: is a section through the nano-motor;
[0025] FIG. 3: is section A-A;
[0026] FIG. 4: is a sectional depiction of the expansion unit;
[0027] FIG. 5: is an expansion unit coiled in a spiral; and
[0028] FIG. 6: is a section through another embodiment of the nano-motor.
[0029] In a first exemplary embodiment, the inventive artificial muscle
comprises the nano-motors 1 (nano power cells), which are formed from
symmetrical individual plates 4 formed as double triangle segments and
arranged radially in a honeycomb shape that are displaceable in the
center and that have an expansion unit 5 inside. The outer ends are
welded. Thus each nano-power cell 1 comprises six double triangle
segments (individual plates 4) that are arranged in a honeycomb shape and
that form the inner shell 2 and enclose the expansion unit 5 (FIG. 1).
[0030] The intermediate space between the expansion unit 5 and the
triangle segments 4 has a filling mass 6 that leads to the immediate
change in the outer shell 8 when the expansion unit 5 expands (FIGS. 2
and 3).
[0031] The length of the nano-power cell 1 will be approximately four to
six millimeters, depending on the application, for instance muscular
structures for a prosthetic. The diameter depends on the number of coils
for the plastic film that forms the expansion unit 5 and is between three
and four millimeters when not expanded.
[0032] In order to return the nano-power cells 1 to their original state
after expansion, they are enclosed by a slightly compressible material
that simultaneously forms the insulator for the applied voltage.
[0033] Because of the volume expansion 7 of the expansion unit 5, the
circumference in the center area of the nano-power cell 1 enlarges.
Because of this expansion, the angle created causes pulling on the outer
ends of the triangle segments 4, which leads to the nano-power cell 1
becoming shorter. This shortening produces the pulling force for the
muscle. The pulling force is indispensable for human and animal skeletal
structures to carry out movement sequences.
[0034] The expansion unit 5 (FIGS. 4 and 5) comprises two spiral-coiled
plastic films that on both sides are conductive and easily expandable.
The plastic films form the field plates (pole 1 and pole 2) 10, 11,
between which the liquid crystals 9 are inlaid. The action of the
expansion unit 5 is amplified because the liquid crystals 9 are inlaid in
the spiral-coiled plastic film. This means that the expansion of the
liquid crystals 9 takes place between the plastic films and between the
coil.
[0035] The expansion of the liquid crystals 9 is produced by applying a
voltage that permits an electrical field to act on the liquid crystals 9.
[0036] The liquid crystals 9 of the ferroelectric elastomers are rectified
by the electrical field according to the field strength, which causes the
volume expansion 7 by a lifting action of the molecules.
[0037] Reducing the field strength causes the liquid crystals 9 to return
to an unordered state.
[0038] The reaction time of the expansion unit 5 can be measured in
milliseconds; therefore a control unit that permits a uniform and adapted
movement sequence must be employed.
[0039] The nano-power cell 1 is supplied with the control voltage for the
electrical field via plug-in connectors/couplings 3 that are attached at
both ends of the cell. The plug-in connectors 3 are connected to the
expansion unit 5 via a flexible connection line.
[0040] The ends of the nano-power cells 1 are used as plug-in connectors
that simultaneously act as a respective coupling 3 between the individual
nano-power cells 1.
[0041] The intermediate space between the expansion unit 5 and the
triangle segments 4 provides the space required for the radial expansion
of the cylindrical rubber comprising nematic elastomers (FIG. 6).
[0042] The length of the nano-power cell 1 will be approximately four to
six millimeters, depending on the application, for instance muscular
structures for prosthetics.
[0043] In order to return the nano-power cells 1 to their original state
after expansion, they are enclosed by a slightly compressible material
that simultaneously forms the insulator for the applied voltage. In the
case of the nematic elastomers, adding heat or light causes shortening of
the nano-power cell 1. Because of its honeycomb-shaped structure, the
radial circumference of the nano-power cell 1 is enlarged at the center.
[0044] This shortening produces the pulling force for the muscle. The
pulling force is indispensable for human and animal skeletal structures
to carry out movement sequences.
[0045] The expansion unit 5, as a contraction rubber, is embodied
comprising a nematic elastomer coil 13 with inlays of liquid crystals.
The expansion unit 5 has a structure comprising a cylindrical hollow
body. The latter is provided all the way around with at least one nematic
elastomer coil 13 running along the surface of the hollow body. A heating
device or laser light source 14 is arranged inside the hollow body and is
connected to the mechanical couplings 3 by means of the electrical
connections. The hollow body and carrier of the elastomers is connected
in a non-positive fit to the outer coupling elements.
[0046] The action of the expansion unit 5 is generated by inlaying the
liquid crystals in the nematic elastomer coil 13.
[0047] By applying a voltage to the heating device or laser light source
14, the nematic elastomer coil 13 is heated or excited so that it draws
into itself and a radial expansion 12 of the outer shell occurs. Reducing
the voltage on the heating device or laser light source 14 causes the
nematic elastomer coil 13 to return to its original state. The nano-power
cell 1 is extended and thus the radial expansion 12 is reduced.
[0048] The reaction time for the expansion unit 5 is about 200
milliseconds, so a control unit that enables a uniform and adapted
movement sequence must be employed.
[0049] The nano-power cell 1 is supplied with the working voltage for the
heating device or the laser light source 14 via a plug-in
connectors/couplings 3 that are attached to both ends of the cell. The
plug-in connectors 3 are connected to the expansion unit 5 via a flexible
electrical connector 15.
[0050] The ends of the nano-power cells 1 are used as plug-in connectors
that simultaneously act as a coupling 3 between the individual nano-power
cells 1.
[0051] A plurality of nano-power cells 1 to create complex muscle packets
may be arranged as desired in any geometric shape. One must always
proceed from the fact that a muscle packet can only pull. Each
counteraction must be undertaken by a complementary muscle packet.
[0052] When muscle packets are in complex geometric formations, the
control mechanism for all cooperating muscle packets must be stepped in a
correspondingly fine manner. Very small cell structures are created by
employing the nano-motor technology. When a voltage is applied, the
nano-motors 1 cause a volume expansion 7. This causes an expansion of the
muscle cell, which causes a shortening of the muscle cell (nano-power
cell 1).
[0053] In another embodiment, a very small cell structure is created by
employing the nano-motor technology. When a voltage is applied, the
nano-motors 1 cause a contraction of the elastomer rubber (elastomer coil
13). This causes a shortening of the muscle cell, so that a radial
enlargement of the muscle cell (nano-power cell 1) occurs.
[0054] The expansion acts on the six rhombic individual plates 4 that are
arranged in a honeycomb shape. It is not possible to perceive a
significant difference between the combination of the parallel and serial
arrangement of the nano-power cells 1, purely exteriorly, and natural
muscles. In terms of tactile perception, it is possible to come very
close to the consistencies of human muscles.
[0055] The energy demand for the artificial muscle, which comprises a
plurality of nano-power cells 1, is approx. 500 watts at peak power. This
power in needed in order to produce the normal forces e.g. for a person.
A fuel cell unit, which can be obtained in very small sizes, is used. It
is possible to house this fuel cell in the interior of the artificial
bone. The heat that develops from the fuel cell is used for heating the
artificial muscles to body temperature.
[0056] Longitudinal forces are created immediately for all necessary
lifting actions. The honeycomb structure ensures high mechanical
efficiency.
[0057] Rotations can be created by the honeycomb-shaped outer surface
since when this happens there is necessarily mutual stabilization of the
individual elements of the artificial muscle and thus large rotational
forces may be attained.
[0058] High pulling forces may be realized by dividing six rhombic pulling
elements in one honeycomb structure, especially by the ductile behavior
of the individual self-stabilizing rhombic elements.
[0059] Rapid movement sequences may be attained in about 100 milliseconds,
which would be very fast for everyday activities. All movement sequences
are controlled so that both slow and rapid movements are possible.
[0060] The control elements for triggering the cells are purely
electronic. There are no mechanical components required for control, such
as for instance valves. All movement sequences are silent. The voltages
used are less than 25 volts and are not harmful for living organisms like
humans and animals.
[0061] The processor-controlled computer units that are networked to one
another are maintained in the interior of the large bones.
[0062] The software controls continuous movement sequences with
self-learning algorithms.
[0063] The application field of the present invention extends to all
technical applications in which mechanical force-controlled movement
sequences are required.
[0064] The drive of the present invention is significant for bionic fields
of use in order to produce the latest generation of prosthetics. The
advantage of this drive is its great similarity to natural muscular
drives for human and animal body functions. by means of complex control
mechanisms, sensor systems comprising hardware and software, linking to
the nervous system, drive energy from hydrogen fuel cells, and the most
modern connections of natural bone parts to artificial materials for
artificial bone construction.
[0065] The fields of application for the artificial muscle are quite
diverse. It may be employed in prosthetics, internal medicine, robotics,
and in general technical applications with forces that pull
longitudinally.
* * * * *